/*
 *                               POK header
 *
 * The following file is a part of the POK project. Any modification should
 * be made according to the POK licence. You CANNOT use this file or a part
 * of a file for your own project.
 *
 * For more information on the POK licence, please see our LICENCE FILE
 *
 * Please follow the coding guidelines described in doc/CODING_GUIDELINES
 *
 *                                      Copyright (c) 2007-2021 POK team
 */

/* s_asinhf.c -- float version of s_asinh.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#ifdef POK_NEEDS_LIBMATH

#include "math_private.h"
#include <libm.h>
#include <types.h>

static const float one = 1.0000000000e+00, /* 0x3F800000 */
    ln2 = 6.9314718246e-01,                /* 0x3f317218 */
    huge = 1.0000000000e+30;

float asinhf(float x) {
  float t, w;
  int32_t hx, ix;
  GET_FLOAT_WORD(hx, x);
  ix = hx & 0x7fffffff;
  if (ix >= 0x7f800000)
    return x + x;        /* x is inf or NaN */
  if (ix < 0x31800000) { /* |x|<2**-28 */
    if (huge + x > one)
      return x; /* return x inexact except 0 */
  }
  if (ix > 0x4d800000) { /* |x| > 2**28 */
    w = __ieee754_logf(fabsf(x)) + ln2;
  } else if (ix > 0x40000000) { /* 2**28 > |x| > 2.0 */
    t = fabsf(x);
    w = __ieee754_logf((float)2.0 * t +
                       one / (__ieee754_sqrtf(x * x + one) + t));
  } else { /* 2.0 > |x| > 2**-28 */
    t = x * x;
    w = log1pf(fabsf(x) + t / (one + __ieee754_sqrtf(one + t)));
  }
  if (hx > 0)
    return w;
  else
    return -w;
}
#endif
